New clinical guidelines, endorsed by the American Association of Neurological Surgeons and the Congress of Neurological Surgeons, recommend the use of two specific DBS techniques for the treatment of severe OCD.
DBS is Deep Brain Stimulation, or the electrical stimulation of targeted parts of the brain via surgically placed electrodes. Over the past ten years evidence has accumulated that DBS can relieve OCD symptoms in people who have not responded to other treatment modalities.
What the Evidence Indicates
After analyzing the available clinical evidence Dr. Clement Hamani and colleagues at Toronto Western Hospital concluded that DBS involving bilateral stimulation (both sides of the brain) should be offered to carefully selected OCD patients, even as further DBS research continues.
The investigators identified that bilateral stimulation of either the nucleus accumbens or the subthalamic nucleus effectively relieved stubborn OCD symptoms. During high quality clinical trials, each technique reduced OCD symptoms about 30 percent by standard OCD rating scales.
The nucleus accumbens plays a vital role in our brain’s reward circuit. It functions primarily with the neurotransmitters dopamine and serotonin. The subthalamic nucleus is related to motor control and is the preferred target of DBS in the treatment of Parkinson’s disease.
Hamani’s review states that bilateral DBS is a “reasonable therapeutic option” for treating severe OCD symptoms unresponsive to other treatments, and that there is not enough evidence to support the implanting of unilateral DBS electrodes - on one side of the brain - in OCD patients.
Moving Forward with Caution
Although reputable studies were analyzed for this review, Hamani notes that most clinical DBS trials for OCD involve a limited number of patients. Clearly more research is needed, particularly to establish the best brain targets, and which subgroups of OCD patients will likely benefit from the surgery.
The FDA approves DBS for OCD, despite limited clinical studies, under a humanitarian device exemption clause. Multiple safeguards have been put in place to ensure only qualified candidates for the procedure are considered.
For the 40 to 60 percent of individuals whose OCD symptoms are unrelieved by psychotherapy and medication, DBS is an option to judiciously explore. The risks involved with surgery need to be carefully considered against the chances of symptom reduction.
Source: Science Daily
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